The present invention relates to a process for fabricating a power semiconductor device and more particularly a III-nitride power semiconductor device.
A well known la-nitride power semiconductor device includes a substrate, a III-nitride transition layer, and a heterojunction III-nitride device over the transition layer. It is also well known to have an insulated gate over the heterojunction. The insulated gate includes a gate dielectric and a gate electrode.
During the fabrication of a III-nitride device it may be necessary to deposit an etch stop body and selectively remove the etch stop body to make an opening for a gate electrode over the gate dielectric. It is difficult to remove the etch stop body completely without damaging the gate dielectric. Consequently, residual etch stop material may be left over the gate dielectric which may cause undesirable interface states that cause variations in the pinch off or threshold voltage.